Kernel memory leak in 8.2-PRERELEASE?
Andriy Gapon
avg at FreeBSD.org
Wed Apr 6 10:14:06 UTC 2011
on 05/04/2011 21:37 Matthias Andree said the following:
> Am 05.04.2011 15:51, schrieb Andriy Gapon:
>
>> Boris,
>> ARC is an adaptive cache (as its name says), but the adaption doesn't happen
>> instantly. So, when your applications do not use a lot of memory, but there is
>> steady filesystem usage, then ZFS ARC is going to gradually grow to consume an
>> optimum amount of RAM. Then, your applications suddenly need a lot more memory,
>> they put pressure on VM system, ARC starts to shrink. But if memory demand grows
>> faster than ARC shrinks, you are going to get a memory shortage. And since you
>> don't have any swap to act as a safety net, you are getting out-of-memory situation.
>> So no surprises here, no system problems, just a normal foot-shooting :)
>>
>> Clamping maximum ARC size, as Jeremy has suggested, should help some.
>> Adding some swap would help a lot more.
>
> The problem to me seems that ARC, the way you describe it, isn't really
> integrated with the system.
Define "really integrated".
> It's not buffer or cache memory, but some
True.
> separate application memory that can't adapt as quickly to system memory
> demands as all other kernel-managed caches and buffers can.
Other kernel-managed caches and buffers are not instant either.
But I have never compared "speed of adaptions".
--
Andriy Gapon
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